Method and apparatus for producing film roll, and film roll

ABSTRACT

A method for producing a film roll of a wound film substrate includes, a spacer placing step for placing belt-like spacers respectively at both sides of the film substrate and at a middle portion of the film substrate between the sides such that the spacers extend in a longitudinal direction of the film substrate, and a winding step for winding the film substrate together with the placed spacers.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and an apparatus for producing a film roll, and a film roll, and in particular to a technique for winding a film substrate that is used for producing display panels such as liquid crystal displays or organic electroluminescence displays and is a constituent of a film roll.

2. Description of the Related Art

In recent years, flexible display panels using a flexible substrate such as a plastic substrate have been developed in the field of liquid crystal displays or organic electroluminescence displays, etc. For producing such flexible display panels, a roll-to-roll system where the flexible substrate may be continuously processed is preferred in terms of productivity.

In the roll-to-roll system, for example, since a film substrate with a length of hundreds of meters is wound around a delivery roll and take-up roll, it could happen that surfaces of the film substrate contact each other or that a thin film or the like having been formed on the surfaces of the substrate is damaged by winding the substrate with foreign substances contacting or adhering to layers thereof.

Therefore, a method has been provided for producing a film roll by winding a film substrate while supplying the film substrate with spacers such that surfaces of the film substrate are prevented from contacting one another.

For example, Japanese Published Unexamined Application No. 2004-199643 discloses a method for producing a conductive film roll in which a transparent conductive film is wound around a roll core while spacers are supplied to both sides of the film. Described therein is that damage to the conductive film caused by foreign substances may be suppressed since the supplied spacers enable reduction of pressure applied to the transparent conductive film.

By the way, in producing flexible display panels, patterning is performed precisely. When surfaces of a film substrate contact one another, damaged portions are caused in conductive elements having been formed on the surfaces of the substrate, resulting in a decline in display quality. For example, as described in the Japanese Published Unexamined Application No. 2004-199643, placing spacers only at both sides could still result in mutual contact of substrate surfaces because of a flexure of the substrate itself to cause damage portions in conductive elements on the substrate surfaces and a decline in display quality of display panels.

In order to solve this problem, using spacers having larger thicknesses is conceivable. However, as the spacers have larger thicknesses, the diameter of a resultant film roll of a film substrate becomes larger, and thereby a production apparatus necessarily becomes larger. It is not preferable to use spacers having larger thicknesses since enlargement of the production apparatus has a significant problem particularly when it is a vacuum-based production apparatus.

SUMMARY OF THE INVENTION

In order to overcome the problems described above, preferred embodiments of the present invention prevent enlargement of the diameter of a film roll and secure a non-contact state of substrate surfaces.

In preferred embodiments of the present invention, in order to achieve the above-described advantages, belt-like spacers are placed respectively at both sides of a film substrate and a middle portion between the sides such that the spacers extend in a longitudinal direction of the film substrate.

A specific method for producing a film roll according to a preferred embodiment of the present invention is a method for producing a film roll of a wound film substrate, including a spacer placing step for placing belt-like spacers respectively at both sides of the film substrate and at a middle portion of the film substrate between the sides such that the spacers extend in a longitudinal direction of the film substrate, and a winding step for winding the film substrate together with the placed spacers.

According to the above-described method, in the spacer placing step, a spacer is placed at a middle portion in the transverse dimension of a film substrate where surfaces of the film substrate are more likely to contact one another when the film substrate is wound, and thereby mutual contact of the surfaces of the film substrate is prevented and suppressed even when the film substrate is wound in the winding step. Also, enlargement of the diameter of a film roll is prevented and suppressed since the same spacer as spacers placed at both sides of the film substrate is placed at the middle portion of the film substrate in order to prevent the mutual contact of the surfaces of the film substrate. It is thus enabled to prevent and suppress the enlargement of the diameter of the film roll and secure the non-contact state of the substrate surfaces.

The film substrate includes a plurality of display panel formation regions arranged in a matrix for forming display panels, and the spacer at the middle portion may be placed between the display panel formation regions.

According to the above-described method, placing spacers on a film substrate has less influence on the film substrate that is a constituent of a film roll since the spacer at the middle portion of the film substrate is placed between a plurality of display panel formation regions.

The spacer at the middle portion may have a width smaller than that of each of the spacers at the sides of the film substrate.

According to the above-described method, placing a spacer with a smaller width at a middle portion of a film substrate has specific effects and advantages of preferred embodiments of the present invention since conductive elements formed at the middle portion of the film substrate are generally finer than those formed at the sides thereof.

Each of the spacers may have a width of about 1 mm to about 50 mm, for example.

The above-described method achieves the specific effects and advantages of preferred embodiments of the present invention. When each of spacers has a width smaller than about 1 mm, placing the spacers at predetermined positions of a film substrate would be more difficult. When each of the spacers has a width larger than about 50 mm, the film substrate would have more unavailable regions thereon.

Each of the spacers may have a thickness of about 0.25 mm to about 1 mm, for example.

The above-described method achieves the specific effects and advantages of preferred embodiments of the present invention. When each of spacers has a thickness smaller than about 0.25 mm, surfaces of a film substrate would be more likely to contact one another. When each of the spacers has a thickness larger than about 1 mm, the diameter of a film roll of the wound film substrate would be larger.

Also, a film roll production apparatus according to a preferred embodiment of the present invention is a film roll production apparatus for producing a film roll of a wound film substrate, including a rotatable roll core for winding the film substrate, and spacer introduction reels on which respective belt-like spacers are to be wound and which are respectively located at positions corresponding to both sides and a middle portion of the film substrate that is to be wound around the roll core such that the spacers are introduced from the spacer introduction reels onto the film substrate that is to be wound around the roll core.

According to the above-described structure, with the use of such spacer introduction reels, a spacer is placed at a middle portion in the transverse dimension of a film substrate where surfaces of the film substrate are more likely to contact one another when the film substrate is wound, and thereby mutual contact of the surfaces of the film substrate is prevented and suppressed even when the film substrate is wound around a roll core. Also, enlargement of the diameter of a film roll is prevented and suppressed since the same spacer as spacers placed at both sides of the film substrate is placed at the middle portion of the film substrate in order to prevent and suppress the mutual contact of the surfaces of the film substrate. It is thus enabled to prevent and suppress the enlargement of the diameter of the film roll and secure the non-contact state of the substrate surfaces.

Each of the spacer introduction reels may be slidable parallel or substantially parallel to a rotation axis of the roll core.

According to the above-described structure, for example, spacers may be placed at a position depending on the position of conductive elements having been formed on a film substrate, and thereby the spacers will have less influence on the film substrate that is a constituent of a film roll.

Moreover, a film roll according to a preferred embodiment of the present invention is a film roll of a wound film substrate, wherein belt-like spacers are placed respectively at both sides of the film substrate and at a middle portion of the film substrate between the sides such that the spacers extend in a longitudinal direction of the film substrate.

According to the above-described structure, a spacer is placed at a middle portion in the transverse dimension of a film substrate where surfaces of the film substrate are more likely to contact one another when the film substrate is wound, and thereby mutual contact of the surfaces of the film substrate is prevented and suppressed even when the film substrate is wound. Also, enlargement of the diameter of a film roll is prevented and suppressed since the same spacer as spacers placed at both sides of the film substrate is placed at the middle portion of the film substrate in order to prevent and suppress the mutual contact of the surfaces of the film substrate. It is thus enabled to prevent and suppress the enlargement of the diameter of the film roll and secure the non-contact state of the substrate surfaces.

According to preferred embodiments of the present invention, it is enabled to prevent and suppress enlargement of the diameter of a film roll and secure a non-contact state of surfaces of a film substrate since belt-like spacers are placed respectively at both sides of the film substrate and at a middle portion between the sides such that the spacers extend in a longitudinal direction of the film substrate.

Other features, elements, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view of a wet etching apparatus according to Preferred Embodiment 1 of the present invention.

FIG. 2 is a perspective view of spacer introduction reels that are constituents of the wet etching apparatus of FIG. 1.

FIG. 3 is a perspective view of a film roll according to Preferred Embodiment 1 of the present invention.

FIG. 4 is a graph showing a contact state of a roll core and a film substrate in an actual example.

FIG. 5 is a cross-sectional view of a coating apparatus according to Preferred Embodiment 2 of the present invention.

FIG. 6 is a perspective view of a film roll according to another embodiment of the present invention.

FIG. 7 is a perspective view of a film roll according to still another preferred embodiment of the present invention.

FIG. 8 is a perspective view of a film roll according to still another preferred embodiment of the present invention.

FIG. 9 is a graph showing a contact state of a roll core and a film substrate in a comparative example.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to the preferred embodiments described below.

Preferred Embodiment 1

FIG. 1 through FIG. 3 show a method and an apparatus for producing a film roll of the present invention, and Preferred Embodiment 1 of the film roll. In the present preferred embodiment, a roll-to-roll wet etching apparatus is illustrated as an apparatus for producing a film roll.

FIG. 1 is a cross-sectional view of a wet etching apparatus 30 a according to the present preferred embodiment.

The wet etching apparatus 30 a includes a first roll housing chamber 21 where a film roll 3 a before processing is housed, an etching process chamber 22 where etching is performed, a rinsing process chamber 23 where rinsing is performed, and a second roll housing chamber 24 where a film roll 3 b after processing is housed, which are arranged in numerical sequence. The wall between the first roll housing chamber 21 and the etching process chamber 22, the wall between the etching process chamber 22 and the rinsing process chamber 23, and the wall between the rinsing process chamber 23 and the second roll housing chamber 24 have openings so that a film substrate 1 which is a constituent of the film roll 3 a may be delivered via guide rolls 14 a through 14 j in alphabetical sequence.

The first roll housing chamber 21 has a spacer take-up roll 10, a film substrate delivery roll 11 and the guide roll 14 a, which are rotatably provided respectively with their rotation axes extending parallel or substantially parallel to one another. Here, the film substrate 1 is wound around the film substrate delivery roll 11 with belt-like spacers 2 a placed respectively at both sides. Thus, the film roll 3 a includes the wound film substrate 1 and the spacers 2 a placed between layers of the film substrate 1.

The etching process chamber 22 has four guide rolls 14 b through 14 e that are rotatably provided with their rotation axes extending parallel or substantially parallel to one another, an etching tank 15 filled with an etching solution for a wet etching process, and an air knife 17 for removing the etching solution remaining on surfaces of the film substrate 1 by blowing compressed air over the surfaces.

The rinsing process chamber 23 has four guide rolls 14 f through 14 i that are rotatably provided with their rotation axes extending parallel or substantially parallel to one another, a rinsing tank 16 filled with a rinsing solution such as pure water for a rinsing process, and an air knife 17 for removing the rinsing solution remaining on the surfaces of the film substrate 1 by blowing the compressed air over the surfaces.

The second roll housing chamber 24 has a guide roll 14 j, a roll core 12, and spacer introduction reels 13 that are rotatably provided respectively with their rotation axes extending parallel or substantially parallel to one another. For example, as shown in FIG. 2, three spacer introduction reels 13 are rotatably provided parallel or substantially parallel to one another to a shaft 13 c disposed parallel to a rotation axis of the roll core 12. FIG. 2 is a perspective view of the spacer introduction reels 13 viewed in the direction of arrow A in FIG. 1. Each of the spacer introduction reels 13 has a core portion 13 a around which a spacer 2 b (2 c) is wound, and a pair of disc guide portions 13 b arranged so as to sandwich the core portion 13 a and prevent dislocation of the spacers 2 b (2 c). Furthermore, the spacer introduction reels 13 are slidable parallel or substantially parallel to the rotation axis of the roll core 12. Thereby, the spacers 2 b (2 c) can be moved depending on the position of display panel formation regions P (described later) on the film substrate 1 such that the film substrate 1 of the film roll 3 b is prevented from being greatly affected by the spacers 2 b (2 c). The belt-like spacers 2 b (2 c) are wound on the spacer introduction reels 13 in advance. Here, the spacer 2 c wound on the spacer introduction reel 13 illustrated in the middle of FIG. 2 has a width smaller than that of the spacers 2 b wound on the spacer introduction reels 13 disposed at both sides.

Next, the operation of the wet etching apparatus 30 a with the above-mentioned structure is described.

In the first roll housing chamber 21 for the first step, the film substrate 1 that is a constituent of the film roll 3 a on the film substrate delivery roll 11 begins to be delivered toward the guide roll 14 a and then into the etching process chamber 22, while the spacer 2 a that is another constituent of the film roll 3 a begins to be delivered toward the spacer take-up roll 10 and wound around the spacer take-up roll 10.

In the etching process chamber 22 for the second step, the film substrate 1 delivered from the first roll housing chamber 21 is guided downward by the guide rolls 14 b and 14 c and then immersed into the etching solution in the etching tank 15 to be etched. Subsequently, the etched film substrate 1 is pulled out of the etching solution by the guide rolls 14 d and 14 e, and the etching solution remaining on the substrate is removed by the air knife 17 during the wind process. Thereafter, the film substrate 1 after removal of the solution is delivered to the rinsing process chamber 23 via the guide roll 14 e.

In the rinsing process chamber 23 for the third step, the film substrate 1 delivered from the etching process chamber 22 is guided downward by the guide rolls 14 f and 14 g and then immersed into the rinsing solution in the rinsing tank 16 to be rinsed. Subsequently, the film substrate 1 is pulled out of the rinsing solution by the guide rolls 14 h and 14 i, and the rinsing solution remaining on the substrate is removed by the air knife 17 during the wind process. Thereafter, the film substrate 1 after removal of the solution is delivered to the second roll housing chamber 24 via the guide roll 14 i.

In the second roll housing chamber 24 for the last step, the film substrate 1 delivered from the rinsing process chamber 23 is guided by the guide roll 14 j to be wound by the roll core 12 as shown in FIG. 3, while the respective spacer introduction reels 13 introduce the spacers 2 b and 2 c between the layers of the film substrate 1 such that they are wound together. Here, the spacers 2 b with a larger width are disposed at the sides of the film substrate 1, and the spacer 2 c with a smaller width is disposed at the middle portion thereof. Now, FIG. 3 is a perspective view of the film roll 3 b viewed in the direction of arrow B in FIG. 1.

Next, a method for producing a film roll using the wet etching apparatus 30 a with the above-mentioned structure is described. The method for producing a film roll of the present preferred embodiment includes a preparing process, a film roll housing process, an etching process, a rinsing process, and a taking up process (spacer placing step and winding step).

Preparing Process

In a roll-to-roll system, a metallic thin film is formed of aluminum, titanium, or the like, by sputtering on a flexible, film-shaped resin substrate, subsequently a resist pattern is formed on the metallic thin film, and then, the resin substrate is wound around the roll core (film substrate delivery roll 11) while supplying the linear spacers 2 a to be sandwiched at the sides thereof. As a result, the film roll 3 a of the film substrate 1 having the metallic thin film and the resist pattern is prepared.

Here, the film substrate 1 that is a constituent of the film roll 3 a is preferably made of a flexible resin, for example, a polyester (PET) resin, a polyimide (PI) resin, a polyethersulfone (PES) resin, or a glass/epoxy fiber-reinforced resin. For example, the film substrate 1 preferably has a thickness of about 0.1 mm to about 0.3 mm, and a width of about 600 mm, for example. As shown in FIG. 3, the film substrate 1 has a plurality of the display panel formation regions P arranged in a matrix for forming respective display panels.

Also prepared are the spacer introduction reels 13 on which the spacers 2 b and 2 c are wound. Here, the spacers 2 a, 2 b, and 2 c can be made of a resin film of a polyester (PET) resin, a polyimide (PI) resin, or a polyethersulfone (PES) resin film, or a dust-proof paper. Moreover, the spacers 2 a, 2 b, and 2 c each preferably have a thickness of about 0.25 mm to about 1 mm, and a width of about 1 mm to about 50 mm, for example. Should the width of the spacers 2 a, 2 b, and 2 c be smaller than about 1 mm, placing the spacers 2 a, 2 b, and 2 c to desired positions on the film substrate 1 would be difficult. Should the width of the spacers 2 a, 2 b, and 2 c be larger than about 50 mm, for example, effective regions on the film substrate 1 available for the display panel formation regions P would be smaller. Should the thickness of the spacers 2 a, 2 b, and 2 c be smaller than about 0.25 mm, the surfaces of the film substrate would be more likely to contact one another. Should the thickness of the spacers 2 a, 2 b, and 2 c be larger than about 1 mm, the diameter of the film roll 3 a and a film roll 3 b to be produced would be larger.

The following processes are continuously performed in the roll-to-roll system, and the respective processes will be described separately in the preferred embodiment below.

Film Roll Housing Process

First, the film roll 3 a is housed in the first roll housing chamber 21, and then the spacer 2 a is pulled out of the film roll 3 a, and the leading end of the spacer 2 a is attached to the take-up roll 10. Next, in the same manner, the film substrate 1 is pulled out of the film roll 3 a, and the leading end of the substrate is passed to the guide roll 14 a. Then, the take-up roll 10 and a film substrate delivery roll 11 are driven.

Etching Process

The film substrate 1 supplied from the guide roll 14 a is received by the guide roll 14 b and delivered via the guide rolls 14 c and 14 d through the etching tank 15 in which the film substrate 1 is etched. In this etching process, a portion of a metallic thin film exposed through a resist pattern on the film substrate 1 is removed such that the metallic thin film has a predetermined pattern. The etched film substrate 1 is pulled out of the etching tank 15, and the etching solution remaining on the substrate surfaces is removed by the air knife 17 before the film substrate 1 is delivered to the guide roll 14 e.

Rinsing Process

The film substrate 1 supplied from the guide roll 14 e is received by the guide roll 14 f and delivered via the guide rolls 14 g and 14 h through the rinsing tank 16 in which the film substrate 1 is rinsed. In this rinsing process, the surfaces of the film substrate 1 are washed with the rinsing solution, and the etching solution remaining on the surfaces of the film substrate 1 is removed with the rinsing solution. The rinsed film substrate 1 is pulled out of the rinsing tank 16, and the rinsing solution remaining on the substrate surfaces is removed by the air knife 17 before the film substrate 1 is delivered to the guide roll 14 i.

Taking Up Process

First, the film substrate 1 supplied from the guide roll 14 i is received by the guide roll 14 j, and the leading end of the substrate is attached to the roll core 12. Next, the spacers 2 b and 2 c wound on the respective spacer introduction reels 13 housed in the second roll housing chamber 24 in advance are pulled out, and then, the leading ends thereof are placed respectively at both sides and a middle portion of the film substrate 1 on the roll core 12 as shown in FIG. 3 (spacer placing step). Furthermore, the roll core 12 and the spacer introduction reels 13 are driven to wind the film substrate 1 around the roll core 12 with the respective spacers 2 b and 2 c (winding step).

As described above, the film roll 3 b can be produced where the belt-like spacers 2 b and 2 c are placed respectively at both sides and a middle portion of the film substrate 1 such that the spacers extend in a longitudinal direction of the film substrate 1.

Next, experiments conducted practically are described.

In an actual example and a comparative example of the present invention, one layer of a film substrate having a titanium thin film formed on one side thereof was wound with spacers having a predetermined thickness around a roll core having a conductive film on a surrounding surface thereof such that the titanium thin film could face the conductive film of the roll core. The contact/non-contact state between the roll core and the film substrate was examined by testing the conductivity between the conductive film of the roll core and the titanium thin film. The contact/non-contact state between the roll core and the film substrate is considered to be equivalent to the contact/non-contact state between the substrate surfaces of the wound film substrate.

Here, the roll core had a diameter of 150 mm. The film substrate was made of a glass/epoxy fiber-reinforced resin, and had a thickness of 0.1 mm to 0.3 mm, a width of 600 mm, a Young's modulus of 5 GPa to 15 GPa, and a specific weight of 1.0 g/cm³ to 2.0 g/cm³. The spacers used were made of a polyimide resin and had six different thicknesses in the range of 0.125 mm to 0.750 mm.

In the actual example, spacers with a width of 10 mm were placed at both sides of the film substrate, and a spacer with a width of 5 mm was placed at a middle portion thereof. On the other hand, in the comparative example, spacers with a width of 10 mm were placed only at both sides of the film substrate.

Graphs of FIG. 4 and FIG. 9 show the results. Here, FIG. 4 and FIG. 9 illustrate the relationship between the tension in a longitudinal direction of the film substrate and the thickness of the spacers, and the contact/non-contact state between the roll core and the film substrate in the actual example and comparative example, respectively. Open circles in the graphs of FIG. 4 and FIG. 9 indicate that the conductive film of the roll core and the titanium thin film of the film substrate were not conducting therebetween, i.e., the non-contact state between the roll core and the film substrate. Closed triangles in the graphs indicate that the conductive film of the roll core and the titanium thin film of the film substrate were conducting therebetween, i.e., the contact state between the roll core and the film substrate.

Specifically, in the actual example of FIG. 4, the non-contact state between the roll core and the film substrate was created when the spacers had a thickness of about 0.25 mm or more. On the other hand, in the comparative example of FIG. 9, the non-contact state between the roll core and the film substrate was created when the spacers had a thickness of 0.40 mm or more. Thus, the actual example showed that the spacers even with a smaller thickness can create the non-contact state of the roll core and the film substrate. Thereby, enlargement of the diameter of a film roll can be prevented and suppressed and the non-contact state between the substrate surfaces can be secured. Note that the non-contact state between the roll core and the film substrate was created when the spacers had a thickness of about 0.25 mm or more in the actual example, but, with a harder material of the film substrate, i.e. with a larger Young's modulus, the non-contact state between the roll core and the film substrate can be created even when the spacers have a thickness smaller than about 0.25 mm.

As described above, according to the present preferred embodiment, in the spacer placing step, the spacer 2 c is placed at a middle portion in the transverse dimension of the film substrate 1 where surfaces of the film substrate 1 are more likely to contact one another when the film substrate 1 is wound, and thereby mutual contact of the surfaces of the film substrate 1 can be prevented and suppressed even when the film substrate 1 is wound in the winding step. Also, the enlargement of the diameter of the film roll 3 b is prevented and suppressed since the spacer 2 c with a same thickness as that of the spacers 2 b placed at both sides of the film substrate 1 is placed at the middle portion of the film substrate 1 in order to prevent and suppress mutual contact of the surfaces of the film substrate 1. Accordingly, it is enabled to prevent and suppress the enlargement of the diameter of the film roll 3 b and secure the non-contact state between the surfaces of the film substrate 1.

Preferred Embodiment 2

FIG. 5 shows Preferred Embodiment 2 of an apparatus for producing a film roll according to the present invention. The present preferred embodiment illustrates a coating apparatus using a roll-to-roll system as an apparatus for producing a film roll. Here, in each of the following preferred embodiments, the same elements as those of FIG. 1 through FIG. 3 are denoted by the same reference numerals used in FIG. 1 through FIG. 3, and the detailed descriptions thereof will be omitted.

FIG. 5 is a cross-sectional view of a coating apparatus 30 b according to the present preferred embodiment.

The coating apparatus 30 b includes a first roll housing chamber 21 where a film roll before processing is housed, a coating chamber 25 where coating is performed, a heating process chamber 26 where heating is performed, and a second roll housing chamber 24 where a film roll after processing is housed, which are arranged in numerical sequence. The wall between the first roll housing chamber 21 and the coating chamber 25, the wall between the coating chamber 25 and the heating process chamber 26, and the wall between the heating process chamber 26 and the second roll housing chamber 24 have openings so that a film substrate 1 which is a constituent of a film roll may be delivered via guide rolls 14 a through 14 j in alphabetical sequence.

The coating chamber 25 has guide rolls 14 k and 14 l that are rotatably mounted with their rotation axes extending parallel or substantially parallel to each other, and a slit coater 18 for coating the surfaces of the film substrate 1 to be delivered on the guide rolls 14 k and 14 l with a thin film made of a resist material or the like.

The heating process chamber 26 has five guide rolls 14 m through 14 q that are rotatably mounted with their rotation axes extending parallel or substantially parallel to one another, a heater (not shown) for heating the film substrate 1 to be delivered via the guide rolls 14 m through 14 q and to bake the thin film on the film substrate 1.

In the coating apparatus 30 b with the above-described structure, after a film roll 3 a is housed in the first roll housing chamber 21 as in Preferred Embodiment 1 and the film substrate 1 that is a constituent of the film roll 3 a is coated with a thin film in the coating chamber 25, the thin film is baked in the heating process chamber 26. In the last step, the film substrate 1 is wound around a roll core 12 in the second roll housing chamber 24 as in Preferred Embodiment 1 to produce a film roll 3 b.

Other Preferred Embodiments

Each of the above-illustrated preferred embodiments of the present invention may have alternative structures described below. FIG. 6 through FIG. 8 show other preferred embodiments of a film roll according to the present invention.

In each of the above-described preferred embodiments, the film roll 3 b includes the spacer 2 c with a smaller width is disposed at the middle portion of the film substrate 1. However, the present invention is not limited to such a structure but may include film rolls 3 c through 3 e as shown in FIG. 6 through FIG. 8, for example.

On the film roll 3 c shown in FIG. 6 specifically, the spacer 2 c at the middle portion and the respective spacers 2 b at the sides of the film substrate 1 have substantially equal widths.

On the film roll 3 d shown in FIG. 7, the spacer 2 c at the middle portion of the film substrate 1 is shifted to the right from the center of the film substrate 1 by sliding the respective spacer introduction reels 13 parallel to the rotation axis of the roll core 12.

Furthermore, on the film roll 3 e shown in FIG. 8, the spacer 2 c at the middle portion of the film substrate 1 has a width larger than that of the respective spacers 2 b at the sides of the substrate.

Thus, placing the spacer 2 c at the middle portion of the film substrate 1 depending on the position of the display panel formation regions P can prevent the film substrate 1 from being greatly affected by the spacer 2 c.

In each of the above-illustrated preferred embodiments, the film rolls 3 b through 3 e each preferably include one spacer 2 c between the sides of the film substrate 1. However, the present invention is not limited to such arrangements but may include a plurality of spacers between the sides of the film substrate 1.

As described above, the present invention can prevent and suppress enlargement of the diameter of a film roll and secure a non-contact state between substrate surfaces and is therefore effective in producing display panels using a roll-to-roll system.

While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims. 

1-8. (canceled)
 9. A method for producing a film roll of a wound film substrate, comprising the steps of: placing belt spacers respectively at both sides of the film substrate and at a middle portion of the film substrate between the sides such that the spacers extend in a longitudinal direction of the film substrate; and winding the film substrate together with the placed spacers.
 10. The method of claim 9, wherein the film substrate includes a plurality of display panel formation regions arranged in a matrix for forming display panels, and the spacer at the middle portion is placed between the display panel formation regions.
 11. The method of claim 9, wherein the spacer at the middle portion has a width smaller than that of each of the spacers at the sides of the film substrate.
 12. The method of claim 9, wherein each of the spacers has a width of about 1 mm to about 50 mm.
 13. The method of claim 9, wherein each of the spacers has a thickness of about 0.25 mm to about 1 mm.
 14. A film roll production apparatus for producing a film roll of a wound film substrate, comprising: a rotatable roll core arranged to wind the film substrate; and spacer introduction reels on which respective belt spacers are to be wound and which are respectively located at positions corresponding to both sides and a middle portion of the film substrate that is to be wound around the roll core such that the spacers are introduced from the spacer introduction reels onto the film substrate that is to be wound around the roll core.
 15. The apparatus of claim 14, wherein each of the spacer introduction reels is slidable substantially parallel to a rotation axis of the roll core.
 16. A film roll of a wound film substrate comprising belt spacers placed respectively at both sides of the film substrate and at a middle portion of the film substrate between the sides such that the spacers extend in a longitudinal direction of the film substrate. 